Assembly with an instrument panel for a motor vehicle and a knee airbag

ABSTRACT

An airbag housing is carried on a formed part extending from a lower section of an instrument panel for a motor vehicle. The formed part forms at least a front section of an upper wall of a footwell assigned to the vehicle occupants. A knee air-bag is disposed in the airbag housing.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No. 12/072,221 filed on 25 Feb. 2008. The entire disclosure of the above application is incorporated herein by reference.

FIELD

The present disclosure relates to an assembly with an instrument panel for a motor vehicle and a knee airbag.

BACKGROUND

The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.

An assembly of the generic type is described, for example, in U.S. Pat. No. 6,217,059 B1 or US 2002/0171231 A1. Here, the housing which accommodates the airbag is located on the inner side of a lower section of the instrument panel and is rigidly fixed to this. The exit opening of the housing for the airbag here lies opposite the knee-shin area of the vehicle occupant to be protected, in other words of the driver or the passenger, and is basically parallel to the surface of the instrument panel. In case of operation, the knee airbag is inflated between the instrument panel and the knee-shin area of the vehicle occupant to be protected. The knee airbag serves primarily to prevent the forward movement of the pelvis of a vehicle occupant, in particular of a vehicle occupant who is not wearing a seat belt, from being displaced forwards in case of a frontal collision.

SUMMARY

The significance of a knee airbag for the overall safety concept of a motor vehicle differs from region to region. In particular in the USA, where the wearing of seatbelts may not be a legal obligation, and where it is often unusual to wear a seat belt, the significance of the knee airbag for the safety concept of a motor vehicle is often extremely high. In Europe, in contrast, where the legal obligation to wear a seatbelt is generally observed, the significance of the knee airbag for the safety concept of a motor vehicle is often slight, or it can be more useful to save the weight of the knee airbag unit and to invest it in another safety device.

This means that it is often the case that one and the same vehicle type is offered in the USA with knee airbag, but in Europe without.

This again results in the need for development and manufacture of different instrument panels for one and the same type of vehicle. Because of the size and complexity of the instrument panels, this leads to a very great deal of additional development and manufacturing work, with the associated costs.

Starting from this point, the present teachings have the task of improving the generic type of assembly in such a way that the development and manufacturing time and expense is decreased, if a vehicle type is to be offered with the equipment variants with and without knee airbag.

According to the present teachings, the housing is not located on or in the instrument panel, but on a formed part which follows on from the lower section of the instrument panel. Generally, therefore, this formed part forms at least the front section of the upper wall of the footwell which is assigned to the vehicle occupants. Because the housing of the knee airbag is no longer a part of the instrument panel or is connected with it, the same instrument panel can always be used, independently of whether the vehicle is to be fitted with a knee airbag or not. It is only necessary to stock two differently-formed parts, which, however, are considerably smaller and considerably less complex than the instrument panel. It is even possible always to make use of the same formed part, and, for the case that no knee airbag is to be used, to make use of an additional cover element which covers the exit opening of the housing. Such a process becomes even more simple, as the exit opening of the housing in the arrangement according to the disclosure can lie in an area which is not seen by the vehicle occupants, so that excessive time and expense with regard to a visible gap and similar can be avoided.

As, during the expansion of an airbag, i.e. when the gas generator which inflates the airbag is operated, considerable forces occur, as is already known, it is often to be preferred if the formed part which bears the housing is directly linked with a lateral strut of the motor vehicle.

In order to prevent gaps, the formed part should be connected with the instrument panel. For reasons of simple assembly, it is preferred that at least one part of the necessary connection elements is in the form of a clip connection.

The housing which accommodates the knee airbag can be a separate component which is connected with the formed part, or the housing can be an integral component of the formed part.

Further embodiments of the present teachings result from the further subclaims as well as from the embodiments now described in more detail by means of the Figures. The Figures are as follows:

Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

DRAWINGS

The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

FIG. 1 is a lengthways section through the front area of an occupant cabin of a motor vehicle in schematic form;

FIG. 1 a illustrates the items shown in FIG. 1 in an equipment variant without a knee airbag;

FIG. 2 illustrates the items shown in FIG. 1 with the knee airbag inflated;

FIG. 3 illustrates the lower part of an instrument panel, a formed part and a steering column in a perspective view;

FIG. 4 illustrates the items shown in FIG. 3 in a different perspective;

FIG. 5 illustrates the formed part from FIGS. 3 and 4;

FIG. 6 illustrates the formed part from FIG. 5 in a bird's eye view from Direction A;

FIG. 7 illustrates the lower part of an instrument panel and a formed part according to a second embodiment of the invention in a side view;

FIG. 8 illustrates the items shown in FIG. 1 during inflation of the knee airbag, whereby the upper end of the knee airbag is connected with the housing by means of a capture tape; and

FIG. 9 illustrates the items shown in FIG. 8 with the knee airbag fully expanded.

DESCRIPTION OF VARIOUS ASPECTS

The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.

FIG. 1 shows a schematic section through the front passenger side of a motor vehicle. In front of vehicle seat 19 there is instrument panel 10, under which footwell 50 is located. In the normal seat position, the knee-shin area 42 of passenger 40 is located in front of a lower section of instrument panel 10. The knee-shin area 42 is hereby at a distance from instrument panel 10.

As can be seen from FIG. 2, a knee airbag 32 is present which is inflated by a gas generator 30 in case of a frontal collision. At least a part of this knee airbag 32 is located in fully expanded state between the knee-shin area 42 of occupant 40 and a lower section of instrument panel 10. In particular when the passengers or drivers are not belted in, knee airbag 32 prevents forward movement of the pelvis. Furthermore, collision of the sensitive knee-shin area 42 against instrument panel 10 is prevented.

As can be seen from FIGS. 1 and 2, housing 22 of the knee airbag unit is located on a formed part 20, which extends from the lower section of instrument panel 10 in the direction of the front of the vehicle, and hereby forms at least a part of the ceiling of footwell 60. Formed part 20, which in general is an injection moulded part of plastic, hereby lies basically horizontal. Housing 22 can be an integral part of formed part 20, or housing 22 can be a separate component, which is rigidly connected with formed part 20. Footwell cladding 18 follows on at the rear section of formed part 20.

In comparison with instrument panel 10, formed part 20 is a small and mechanically simple component. This means that only a comparatively slight expenditure of cost and effort is required to manufacture it in a version with airbag unit (see FIG. 1) and in a version without airbag unit (see FIG. 1 a). By these means, on the other hand, it is easy in one and the same type of vehicle to manufacture a version with knee airbag and a version without knee airbag. It is only necessary in final assembly with the first vehicle version to mount the first type of formed part 20 and in the second vehicle version to mount the second type of formed part connected to instrument panel 10. If the version with knee airbag unit is selected, this generally can be connected to the same sensor system as the front airbag, which is always present.

FIGS. 3 to 6 show a first concrete embodiment of formed part 20, whereby FIGS. 3 and 4 show formed part 20 in its mounted state at a lower section of instrument panel 10 and FIGS. 5 and 6 show the formed part in its non-mounted state. It can be seen, that here the knee airbag is the knee airbag for the driver's side. The structure of formed part 20 will now be explained in relation to FIGS. 5 and 6.

In the area of the front edge, there are latching elements 26 over which formed part 20 can be latched on instrument panel 10. Immediately behind latching elements 26 is housing 22, formed in one piece onto formed part 20, in which the knee airbag and the gas generator are accommodated. Housing 22 continues to exhibit a cover 24 on the rear side, which covers a rear opening. The gas generator and the knee airbag are mounted through this rear opening. Basically opposite to this rear cover 24 is the exit opening for the knee airbag, not shown here, which is closed by a cover element. This cover element can be formed in one piece with formed part 20 and can be surrounded by a set break line.

Next to housing 22 are fixing holes 23, through which screws extend when in mounted state, which are screwed together with instrument panel 10. Together with latching elements 26, a sufficiently stable fixing of formed part 20 to instrument panel 10 results (see also FIG. 3). The fixing element here basically surrounds housing 22, so that the forces which occur during expansion of the airbag can also be absorbed. Because of the inherent stiffness of formed part 20 it is not necessary to provide additional fixing elements on the rear section of formed part 20.

This means that mounting of the formed part on instrument panel 10 is extremely simple, as can particularly be seen in FIGS. 3 and 4: first formed part 20 with its latching elements 26 is latched onto the instrument panel 10 which is generally already mounted in the vehicle and then screwed together. By means of this modular structure, it is particularly also possible to retrofit a knee airbag to a vehicle which was originally supplied in the version without knee airbag. It is only necessary to exchange the formed part which was originally mounted, which does not exhibit a knee airbag, for a formed part with a knee airbag unit, and to connect the gas generator to the existing sensor system. As formed part 20, as already mentioned, forms the ceiling or a part of the ceiling of footwell 60, therefore formed part 20 exhibits through-holes 28 for ventilation.

FIG. 7 shows a concrete version of the second embodiment of the invention. Here, formed part 20 extends fully horizontally, so that the exit opening for knee airbag 32 lies in a horizontal plane. This has the particular advantage that the transitional point between the lower section of instrument panel 10 and formed part 20 cannot be seen by the vehicle occupants, so that here a relatively wide gap can be provided. It is possible to see here also that formed part 20 follows on directly from a lateral strut 50 of the motor vehicle, with which it is preferably also directly connected. This means that forces which occur when the knee airbag expands are led directly into this lateral strut, without placing stress on instrument panel 10. The invention is shown here using a knee airbag unit for the passenger; the glove compartment 14 of instrument panel 10 can be seen. Formed part 20 can in particular be an injection moulded or deep-drawn part of plastic.

As can be seen in FIGS. 8 a and 9, a capture tape can be present running outside knee airbag 32, which helps to position knee airbag 32 between instrument panel 10 and knee-shin area 42 of the vehicle occupants. Such a capture tape 34 can be necessary, as depending on the particular embodiment, in particular in the embodiment shown in FIG. 7, the exit opening for knee airbag 32 is located fairly far away from the knee-shin area 42 of the vehicle occupants.

While specific examples have been described in the specification and illustrated in the drawings, it will be understood by those skilled in the art that various changes may be made and equivalence may be substituted for elements thereof without departing from the scope of the present teachings as defined in the claims. Furthermore, the mixing and matching of features, elements and/or functions between various examples may be expressly contemplated herein so that one skilled in the art would appreciate from the present teachings that features, elements and/or functions of one example may be incorporated into another example as appropriate, unless described otherwise above. Moreover, many modifications may be made to adapt a particular situation or material to the present teachings without departing from the essential scope thereof. Therefore, it may be intended that the present teachings not be limited to the particular examples illustrated by the drawings and described in the specification as the best mode of presently contemplated for carrying out the present teachings but that the scope of the present disclosure will include any embodiments following within the foregoing description and any appended claims. 

What is claimed is:
 1. An assembly for a motor vehicle comprising: an instrument panel; a formed part extended from a lower section of the instrument panel; a housing carried on the formed part; and an airbag in the housing when stored and which on activation is inflated between the lower section of the instrument panel and a knee-shin area of a vehicle occupant to be protected.
 2. The assembly according to claim 1, wherein the formed part forms at least part of a ceiling of a footwall for the vehicle occupant.
 3. The assembly according to claim 1, wherein the housing defines an exit opening for the airbag, the exit opening disposed in a horizontal plane.
 4. The assembly according to claim 1, wherein the formed part is connected with the instrument panel.
 5. The assembly according to claim 4, wherein the formed part is latched together with the instrument panel by clip connections.
 6. The assembly according to claim 1, wherein the formed part is directly connected with a transverse strut of the motor vehicle.
 7. The assembly according to claim 1, wherein the formed part is selected from a group including an injection moulded part and a deep-drawn part of plastic.
 8. The assembly according to claim 1, wherein the housing is an integral part of the formed part.
 9. The assembly according to claim 1, wherein the housing is a separate element which is connected with the formed part. 